Due to increasing incidence of cancer, in general, there is need to develop new therapeutic strategies. The current methods for treatment of tumors, besides radiation therapy and surgical interventions, include tumorcidal chemotherapeutic agents which act directly and are toxic to tumor cells. Such anti-tumor drugs, however, are generally associated with severe side effects as they often kill all normally dividing cells without discrimination. The present invention relates to an alternate strategy, referred to as immunomodulatory therapy, where instead of killing the tumor cell directly the drug is intended to act on the immune system and activate its effector mechanisms which in turn kills tumor cells. Immunomodulatory therapy thus relates to "educating" or "activating" the immune cells to react against and kill the tumor cells; the same strategy applies also to cells infected with parasites and/or viruses. The advantage is that the immune system is selective and it normally attacks only diseased/tumor cells, ignoring the normal healthy ones.